Dual centrifugal fan structure and heat dissipation device having the fan structure

ABSTRACT

A dual centrifugal fan structure having a first centrifugal fan, a second centrifugal fan, and a housing is disclosed. The housing is a hollow enclosure divided into a first chamber and a second chamber for installing the first and second centrifugal fans, respectively. The first and second chambers have first and second air inlets, respectively. The housing further includes an air outlet.

BACKGROUND OF THE INVENTION

The present invention relates in general to dual centrifugal fanstructure and a heat dissipation device for the fan structure, and moreparticularly, to a fan structure having two centrifugal fans and a heatdissipation device having the fan structure.

FIG. 1 shows a conventional heat dissipation device 1 a applied to acentral processing unit (CPU) 2 a. The heat dissipation device 1 acomprises a heat sink 10 a and an axial-flow fan 11 a. The heat sink 10a includes a substrate 100 a attached to the top surface of the centralprocessing unit 2 a and a plurality of vertical fins 101 a integrallyformed on the substrate 100 a. The axial-flow fan 11 a is mounted on thefins 101 a. Therefore, when the central processing unit 2 a isoperating, the heat generated thereby is conducted towards the fins 101through the substrate 100 a and circulated by the fan 11 a to beabsorbed by ambient air.

The upgraded technology provides more powerful functions and fasteroperation speed of the central processing unit 2 a. As a consequence,the heat generated thereby is increased. However, the overall heatdissipation efficiency of the conventional heat dissipation device doesnot comply with the increased heat. Further, as the air generated by theaxial-flow fan 11 a is circulated downwardly, the heat cannot bedissipated to the ambient.

Therefore, there exist deficiency for practically application of theabove-mentioned conventional heat dissipation device. There is thus asubstantial need to provide a dual centrifugal fan structure and a heatdissipation device having the fan structure that resolves the abovedrawbacks and can be used more conveniently and practically.

SUMMARY OF THE INVENTION

The present invention provides a dual centrifugal fan structure and aheat dissipation device having the fan structure. The fan structure hastwo fans arranged in parallel with each other for heat dissipation, suchthat the overall heat dissipation efficiency of the heat dissipationdevice is enhanced.

The centrifugal fan structure provided by the present invention includesa first centrifugal fan, a second centrifugal fan, and a housing. Thehousing is a hollow enclosure divided into a first chamber and a secondchamber for installing the first and second centrifugal fans,respectively. The first and second chambers have first and second airinlets, respectively. The housing further comprises an air outlet.

The present invention further provides a heat dissipation device whichcomprises a heat sink, a wind mask mounted on the heat sink, and a firstand second centrifugal fans are arranged in parallel on top of the windmask.

These and other objectives of the present invention will become obviousto those of ordinary skill in the art after reading the followingdetailed description of preferred embodiments.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, and are intended toprovide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF ACCOMPANIED DRAWINGS

The above objects and advantages of the present invention will be becomemore apparent by describing in detail exemplary embodiments thereof withreference to the attached drawings in which:

FIG. 1 shows the operation status of a conventional heat dissipationdevice;

FIG. 2 is an exploded view of a heat dissipation device in a firstembodiment of the present invention;

FIG. 3 is a perspective view of the heat dissipation device as shown inFIG. 2;

FIG. 4 is a cross sectional view of the heat dissipation device as shownin FIG. 2;

FIG. 5 is a cross sectional view of a heat dissipation device in asecond embodiment of the present invention;

FIG. 6 is a cross sectional view of a heat dissipation device in a thirdembodiment of the present invention;

FIG. 7 is a cross sectional view of a heat dissipation device in afourth embodiment of the present invention; and

FIG. 8 shows a perspective view of a heat dissipation device in a fifthembodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENT

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or like parts.

As shown in FIGS. 2 and 3, exploded view and perspective view of a heatdissipation device of the present invention. The heat dissipation deviceincludes a dual centrifugal fan structure. In this embodiment, the dualcentrifugal fan structure includes a housing 10, which is divided into afirst chamber 101 and a second chamber 102 arranged in left-hand sideand right-hand side, respectively, as shown in FIG. 4. The fan structurefurther comprises a first centrifugal fan 11 and a second centrifugalfan 12 disposed in the first and second chambers 101 and 102,respectively.

The first and second chambers 101 and 102 include a first air inlet 103and a second air inlet 104 formed at the top of the housing 10. An airoutlet 105 is formed at the bottom of the housing 10. The air outlet 105extends to both first and second chambers 101 and 102.

The first and second centrifugal fans 11 and 12 include centrifugalblades 110 and 120 and motors 111 and 121 for driving the centrifugalblades 110 and 120, respectively. The blades 110 and 120 are orientedtowards opposite directions, such that rotation directions of the firstand second centrifugal fans 11 and 12 are opposite to each other asshown in FIG. 4. The first and second centrifugal fans 11 and 12 aremounted inside of the first and second chambers 101 and 102 by a pair ofsupport arms 106 formed in the first and second chambers 101 and 102.The support arms 106 are also operative to support and interlink themotors 111 and 121 within the first and second chambers 11 and 12.

As shown in FIG. 4, the fan structure includes a wind mask 2 and a heatsink 3. The heat sink 3 includes an aluminum extrusion type heat sink orother types of heat sinks. As shown, the heat sink 3 comprises a thermalconductive substrate 30, a plurality of fins 31 extending from thethermal conductive substrate 30, and a plurality of channels 32 formedbetween the fins 31.

The wind mask 2 is disposed over the heat sink 3 under the dualcentrifugal fan structure 1. The wind mask 2 has a top panel and asidewall extending from a periphery of the top panel. Preferably, thewind mask 2 has an n-shape cross section. The top panel is open with twothrough holes 20 and 21 aligned with the air outlet 105 of the housing10. A protruding rim 100 is formed along a bottom periphery of thehousing 10. A protruding rim 100 is formed to extend outwardly from abottom periphery of the housing 10. A plurality of holes 107 is formedthrough the protruding rim 100, and a plurality of threaded holes 22 areformed through the top panel of the wind mask 2, such that the housing10 can be fitted on top of the wind mask 2 using fastening devices suchas screws extending through the holes 107 and the holes 22 alignedtherewith. The sidewall of the wind mask 2 can also be engaged with thethermal conductive substrate 30 of the heat sink 3 in the same manner.

As shown in FIG. 4, when the heat dissipation device is applied to acentral processing unit (CPU) 4, the fan structure 1 facilitates heatdissipation by activate opposite rotation of the fans 11 and 12, whichthen circulate and dissipate heat generated by the central process unit4 towards two lateral sides of the channel 32 between the fins 33.Thereby, a good heat dissipation effect is resulted.

FIG. 5 shows an operation status of the heat dissipation device. In thisembodiment, the heat sink 3 includes a thermal conductive substrate 30.The thermal conductive substrate 30 has a central spike 33 formed by apair of curves descending towards two elongate sides of the substrate30. Therefore, wind or air generated by the fans 11 and 12 can becirculated towards the channels between the fins 33, such that directimpact of air can be suppressed.

As shown in FIGS. 6 and 7, cross sectional views of the third and fourthembodiments are shown. The first and second air inlets 103 and 104 ofthe housing 10 are formed at two lateral sides of the housing 10 (asshown in FIG. 6) or at the front and rear ends of the housing (as shownin FIG. 7).

FIG. 8 shows the fifth embodiment of the present invention. In thisembodiment, the housing 10 includes separate first housing 10′ andsecond housing 10″, and the fans 11 and 12 disposed in the first andsecond housings 10′ and 10″ are aligned with the vent holes 20 and 21 atthe top of the wind mask 2.

While the present invention has been particularly shown and describedwith reference to preferred embodiments thereof, it will be understoodby those of ordinary skill in the art the various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. A dual centrifugal fan structure, comprising: a first centrifugalfan; a second centrifugal fan; and a hollow housing divided into a firstchamber and a second chamber, wherein the first and second centrifugalfans are disposed within the first and second chamber, respectively, andthe first and second chamber comprise a first air inlet and a second airinlet and an air outlet of the housing.
 2. The structure as claimed inclaim 1, wherein each of the first and second centrifugal fans includesa set of blades and a motor driving the blades, such that the blades ofthe first and second centrifugal fans rotate towards oppositedirections.
 3. The structure as claimed in claim 1, wherein the housingcomprises a rim protruding outwardly and horizontally from a bottomperiphery of the housing.
 4. The structure as claimed in claim 1,wherein each of the first and second chambers includes a support arm formounting the first and second centrifugal fans therein, respectively. 5.The structure as claimed in claim 1, wherein the first and second airinlets are formed at a top of the housing.
 6. The structure as claimedin claim 1, wherein the first and second air inlets are formed at twolateral sides of the housing.
 7. The structure as claimed in claim 1,wherein the first and second air inlets are formed at a front side and arear side of the housing, respectively.
 8. A heat dissipation devicehaving a dual centrifugal fan structure, comprising a heat sink, a windmask mounted on the heat sink, and a first centrifugal fan and a secondcentrifugal fan disposed on the wind mask.
 9. The device as claimed inclaim 8, wherein the heat sink includes an aluminum extrusion heat sink.10. The device as claimed in claim 8, wherein the heat sink includes athermal conductive substrate, a plurality of fins extending from thesubstrate, and a plurality of channels formed between the fins.
 11. Thedevice as claimed in claim 8, wherein the thermal conductive substrateincludes a central spike formed of two curves descending from a peak ofthe central spike towards two elongate sides of the thermal conductivesubstrate.
 12. The device as claimed in claim 8, wherein the wind maskincludes an n-shape frame.
 13. The device as claimed in claim 8, furthercomprising a hollow housing divided into a first chamber and a secondchamber for mounting the first and second centrifugal fans therein,respectively, wherein the first and second chambers comprise a first airinlet and a second air inlet, respectively, and the housing furthercomprises an air outlet.
 14. The device as claimed in claim 13, whereinthe housing comprises a protruding rim extending from a bottom peripherythereof.
 15. The device as claimed in claim 13, wherein the housingfurther comprises a pair of support arms for supporting the first andsecond centrifugal fans within the first and second chambers,respectively.
 16. The device as claimed in claim 13, wherein the firstand second air inlets are formed at a top of the housing.
 17. The deviceas claimed in claim 13, wherein the first and second air inlets areformed at a bottom of the housing.
 18. The device as claimed in claim13, wherein the first and second air inlets are formed at a top of thehousing.
 19. The device as claimed in claim 8, further comprising afirst housing and a second housing for installing the first and secondcentrifugal fans therein, respectively.
 20. The device as claimed inclaim 8, wherein the first and second centrifugal fans each comprises aset of blades and a motor for driving the blades to rotate alongopposite directions.